Field
The present invention relates to a method of manufacturing an electromagnetic wave shield housing.
Related Art
The electromagnetic wave shield housings are frequently used in various fields to shield electronic components accommodated therein from electromagnetic waves. An electromagnetic shield is made of various kinds of metal plate which have a shielding property against electromagnetic waves. For example, JP2013-55298A proposes an electromagnetic wave shield cover which is formed by injection molding in which a metal plate for a shield, which has a thin plate shape of which outer edge is bent, is covered by resin from outside in order to reduce the weight.
However, when injection molding such an electromagnetic wave shield housing, the thin-plate-shaped metal plate is deformed. The deformation of the plate happens because the shielding metal plate receives a pressure resulting from a flow of resin when injecting the resin (hereinafter, referred to as “the resin flow pressure”). This resin flow pressure acts on each part of the shielding metal plate from outside when injecting the resin from outside the shielding metal plate. Thus, a plate outer edge which is the bent portion of the shielding metal plate may be further bent inwardly when receiving the resin flow pressure from outside, and thereby the original posture of the plate outer edge may change. The further bending of the plate outer edge can be avoided if the shielding metal plate is made thicker; however, the weight reduction effects will be lost. Therefore, a method of manufacturing an electromagnetic wave shield housing came to be demanded, which does not cause the change in the posture of the plate outer edge of the shielding metal plate, while achieving the weight reduction.